Best bet is to go wander around your local Cash Converters or Cash Generator and get a Sky multiroom box. It is about a third the size of a standard Sky+HD box as it does not have a recording facility but otherwise is near identical electronically. If you are lucky - and most times you will be - it will still have an expired subscription card in it which will get you your local channels on the right numbers. (It will still work without a card but 101 will be BBC London and 103 will be ITV Central West.) Expect to pay less than £20 with remote and usually a 15 or 30 day warranty.
For setting up, if you can get an optical compass it helps, and a signal finder which are around a fiver when on offer in Lidl or Aldi. If you have a smartphone download Satellite Finder and Satellite Director both of which are free. One of them - I think the latter - uses the compass and camera in your phone to show you on the screen the exact physical position of the satellite (Astra 28.2E) in the sky. If you can get on line with a tablet or laptop when on site go to
http://www.macfh.co.uk/JavaJive/AudioVisualTV/SatelliteTV/SatelliteGeneral.html
which, when you enter your location, will plot on a OS map or Google maps exactly where to point your dish. [Another part of the same site will also make UK TV aerial alignment much easer.]
Good luck.